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R D Moore

Publications and source records attributed to R D Moore.

At least 19 recordsLinked to original sources
PubMed2025

A genome-wide association study of methamphetamine use among people with HIV.

BACKGROUND: Amphetamine-like stimulants are the most used psychostimulants in the world; methamphetamine use is the most prevalent in people with HIV. Prolonged methamphetamine use can cause lasting damage to the heart, gut, and brain, as well as auditory hallucinations and paranoid thinking. However, relatively little is known about methamphetamine use and its genetic contributors. METHODS: Using genetic information from the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort, we conducted a multi-ancestry genome-wide association study (GWAS) of methamphetamine use among people with HIV (n&#x2009;=&#x2009;1,196 reported ever use, n&#x2009;=&#x2009;4,750 reported never use). RESULTS: No single nucleotide polymorphism was statistically associated with methamphetamine use at the genome-wide level (p&#x2009;<&#x2009;5 * 10-8) in our study. Further, we did not replicate previously suggested genetic variants from other studies (all p&#x2009;>&#x2009;0.05 in our analysis). DISCUSSION: Our study suggests that there is no single strong genetic contributor to lifetime use of methamphetamine in people with HIV enrolled in CNICS. Larger studies with more refined outcome assessment are warranted to further understand the contribution of genetics to methamphetamine use and use disorder. Investigation into social and environmental contributors to methamphetamine use are similarly necessary.

Humans↗
PubMed1992

Intrathecally administered N-methyl-D-aspartate increases persistent hindlimb flexion in rat.

Persistent hindlimb flexion was induced in pentobarbital anesthetized rats using a prolonged, electrical stimulus. Intrathecal (i.t.) N-methyl-D-aspartate NMDA) (1 mM, 5 microliters) applied prior to stimulation increased flexion relative to stimulated controls subsequent to stimulation (156%); 3 days later (109%) and after spinalization at 3 days (91%). Pretreatment with MK-801 (3 mg/kg, i.p.) prevented the enhancement of flexion. Withdrawal latencies to a thermal stimulus also were measured. I.t. NMDA plus stimulation reduced mean latency relative to controls only subsequent to stimulation. Latencies were increased by MK-801 post-injection, post-stimulation and at 3 days. The results suggest that the induction of persistent hindlimb flexion depends upon spinal NMDA receptors.

Animals↗
PubMed1992

Nonlinear modeling of alcohol consumption for analysis of beverage type effects and beverage preference effects.

In a previous report (Kimball and Friedman, Am J Epidemiol, 1992;135:1279-86), linear models for relating health outcomes to alcohol consumption were proposed for differentiating between beverage type effects and beverage preference effects. The models were applied to data relating serum high density lipoprotein cholesterol to alcohol consumption. In this report, those models are extended to the nonlinear case and are applied to data from the 1982 Maryland Hypertension Survey relating systolic blood pressure to alcohol consumption.

Adolescent↗
PubMed1992

Hydroxyurea: effects on hemoglobin F production in patients with sickle cell anemia.

Patients with sickle cell anemia were treated with daily doses of hydroxyurea, to assess pharmacokinetics, toxicity, and increase in fetal hemoglobin (Hb) production in response to the drug. Plasma hydroxyurea clearances were not a useful guide to maximum tolerated doses of the drug. The mean daily single oral dose that could be maintained for at least 16 weeks was 21 mg/kg (range, 10 to 35 mg/kg). Among 32 patients, last HbF levels were 1.9% to 26.3% (mean, 14.9%) with increases in HbF over initial values of 1.4% to 20.2% (mean, 11.2%). The most significant predictors of last HbF were last plasma hydroxyurea level, initial white blood count and initial HbF concentration. Last HbF was not related to beta globin haplotype or alpha globin gene number. No serious toxicity was encountered. Clinically significant bone marrow depression was avoided, and chromosome abnormalities after 2 years of treatment were no greater than those observed before treatment. The period of observation has been too short to evaluate the risk of carcinogenesis. Patient's red cells developed striking macrocytosis. Median red cell Hb concentrations did not change. Hb concentrations increased, on average 1.2 g/dL, but serum erythropoietin levels increased. Patients' body weights increased, and some returned to work or school, but no conclusions regarding therapeutic efficacy could be drawn from this uncontrolled open-label study.

Adult↗
PubMed1992

Nephrotoxicity and ototoxicity of aztreonam versus aminoglycoside therapy in seriously ill nonneutropenic patients.

A randomized double-blind clinical trial was done of aztreonam versus aminoglycoside therapy for the empiric treatment of seriously ill nonneutropenic patients suspected of aerobic gram-negative bacterial infection. Each patient was treated for greater than or equal to 72 h with the study drug. Nephrotoxicity, defined by greater than or equal to 50% increase in baseline serum creatinine, occurred in 12 (15%) of 92 patients receiving aminoglycoside therapy and 1 (1%) of 92 patients receiving aztreonam (P less than .004). More severe nephrotoxicity, defined by greater than or equal to 100% increase in baseline serum creatinine, occurred in 6 (6.5%) of 92 patients receiving aminoglycoside therapy and in 1 of 92 receiving aztreonam (P less than .11). Patients with an elevated baseline total bilirubin level were most likely to develop nephrotoxicity. Auditory toxicity occurred in 2 (7%) of 28 evaluatable patients receiving aminoglycoside therapy and in 1 (3%) of 33 receiving aztreonam (P less than .58). One patient, who received aminoglycoside, developed vestibular toxicity. In nonneutropenic patients believed to be at increased risk for renal dysfunction, aztreonam is a less toxic alternative to aminoglycoside therapy for treatment of suspected aerobic gram-negative infection.

Aminoglycosides↗
PubMed1992

Incidence and natural history of cytomegalovirus disease in patients with advanced human immunodeficiency virus disease treated with zidovudine. The Zidovudine Epidemiology Study Group.

Data were analyzed from a multicenter observational cohort study of 1002 persons with AIDS or AIDS-related complex (ARC) and total CD4 cell count < 0.25 x 10(9)/L treated with zidovudine between April 1987 and April 1988. Cytomegalovirus (CMV) disease developed in 109 patients (10.9%), with a 2-year actuarial risk of 15%. Manifestations included retinitis (93 patients), esophagitis (10), colitis (8), gastritis (1), hepatitis (1), and encephalitis (1). The probability of CMV disease at 2 years for patients with initial counts < 0.1 x 10(9)/L was 21.4%, compared with 10.3% for patients with initial counts > or = 0.1 x 10(9)/L (P < .001). By proportional hazards analysis, baseline CD4 cell count < 0.1 x 10(9)/L, enrollment diagnosis of AIDS, and homosexuality were significantly associated with subsequently developing CMV disease. Median survival after diagnosis of CMV disease was 173 days, and CMV was an independent predictor of death. CMV contributes to AIDS-related morbidity and mortality. As new anti-CMV drugs become available, prophylaxis should be targeted at individuals with CD4 cell counts < 0.1 x 10(9)/L.

AIDS-Related Opportunistic Infections↗
PubMed1992

Evaluation of a model curriculum on substance abuse at The Johns Hopkins University School of Medicine.

Beginning in 1985, The Johns Hopkins University School of Medicine developed a model curriculum on alcohol abuse to enhance the education of medical students in issues related to the abuse of alcohol and other drugs. By 1987, preclinical courses (given in years one and two) reflected the goals of the curriculum; however, integration of the curriculum into the clinical courses (given in years three and four) was only partially successful. This paper reports on nine annual surveys of students (the classes of 1989-1992) that were conducted from 1987 to 1990 to measure the effects of the curriculum, using previously validated instruments to record the students' knowledge, attitudes, beliefs in role responsibility, and confidence in clinical skills. Significant improvements occurred in the students' attitudes, beliefs in role responsibility, and confidence in skills during their preclinical years. These positive changes were stronger, and better sustained during the clinical years, in students who participated in special programs or elective courses focusing on substance abuse; the positive changes were not always sustained in other students. The authors suggest that enhanced experiential sessions, elective programs, and greater emphasis during the clinical years on issues relating to substance abuse are necessary for maintaining the desirable educational outcomes of a substance abuse management curriculum, and that an intensive program against a backdrop of curriculum reform is a useful model.

Baltimore↗
PubMed1992

Nephrotoxicity of high-osmolality versus low-osmolality contrast media: randomized clinical trial.

The comparative frequency of and risk factors for nephrotoxicity with low-osmolality contrast medium (LOM) versus high-osmolality contrast medium (HOM) were investigated. A randomized, double-blind clinical trial was conducted in patients undergoing diagnostic angiocardiography (n = 430) or contrast material-enhanced body computed tomography (CT) (n = 499). Nephrotoxicity was defined as an increase in serum creatinine level that was greater than both 33% and 0.4 mg/dL (40 mumols/L) above the baseline level within 48 hours after the radiologic procedure. The frequency of nephrotoxicity was similar in patients who received LOM versus those who received HOM: 13 of 479 (2.7%) versus 13 of 450 (2.9%), respectively (P = .87), overall; 4.4% versus 4.0% in angiocardiography patients (P = .84); and 1.2% versus 2.0% in body CT patients (P = .35). Factors associated (P less than .05) with increased risk of nephrotoxicity were insulin-dependent diabetes, baseline serum creatinine level greater than 1.5 mg/dL (130 mumols/L), concurrent use of furosemide, and angiocardiographic examination. Patients who have preexisting renal insufficiency may be at higher risk for nephrotoxicity with HOM than with LOM.

Angiocardiography↗
PubMed1992

Incidence and natural history of Mycobacterium avium-complex infections in patients with advanced human immunodeficiency virus disease treated with zidovudine. The Zidovudine Epidemiology Study Group.

To determine the incidence and natural history of Mycobacterium avium-complex infections in persons with advanced human immunodeficiency virus (HIV) infection, we studied a multicenter cohort of 1,020 persons with acquired immunodeficiency syndrome (AIDS) or the AIDS-related complex (ARC) and CD4 cell count < 0.250 x 10(9)/L initially treated with zidovudine between April 1987 and April 1988. M. avium-complex infections developed in 123 (12%) patients during follow-up, with a 2-yr actuarial risk of 19%. Patients with an initial diagnosis of Pneumocystis carinii pneumonia were more likely to develop M. avium-complex infections than patients with an initial diagnosis of another opportunistic disease or of ARC (p = 0.002). Individuals developing M. avium-complex infections had lower baseline CD4 cell counts, hematocrits, lymphocyte counts, and total white blood cell counts than those who did not develop M. avium-complex infection. During follow-up, individuals who developed M. avium-complex infections were more likely to have severe anemia, to experience zidovudine dose reductions, and to die than were patients without M. avium-complex (p < 0.001). By proportional hazards analysis, a baseline CD4 cell count < 0.100 x 10(9)/L, development of severe anemia, P. carinii pneumonia during follow-up, and zidovudine dose interruption were significantly associated with subsequently developing M. avium-complex infection. A proportional hazards analysis of survival showed that M. avium-complex infection, severe anemia, zidovudine dose interruption, occurrence of an opportunistic infection, CD4 cell count < 0.100 x 10(9)/L, baseline AIDS diagnosis, and transfusion independently predicted an increased risk of death.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗
PubMed1992

Pneumocystis prophylaxis and survival in patients with advanced human immunodeficiency virus infection treated with zidovudine. The Zidovudine Epidemiology Group.

BACKGROUND: Pneumocystis carinii pneumonia (PCP) is a major cause of morbidity and mortality in persons with advanced human immunodeficiency virus (HIV) infection. We assessed the impact of prophylaxis for PCP on survival in patients with advanced HIV disease who were treated with zidovudine. METHODS: A cohort of 1048 patients with prior PCP (N = 437), another acquired immunodeficiency syndrome-defining diagnosis (N = 168) or acquired immunodeficiency syndrome-related complex (N = 443) and with less than 0.250 x 10(9)/L CD4 cells initiated zidovudine treatment between April 1987 and April 1988. They were then followed up for 24 months. Morbidity and mortality outcomes were assessed every 2 months. A time-dependent, Cox proportional hazards model was used to identify factors associated with new episodes of PCP and with survival. RESULTS: Three hundred thirty-six patients (32%) developed PCP after beginning treatment with zidovudine, with a 24-month actuarial rate of 41%. Patients with prior PCP were more likely to develop PCP during follow up (40%) than those without a history of PCP at entry (27% with PCP at follow-up). Other factors associated with developing PCP were baseline acquired immunodeficiency syndrome vs acquired immunodeficiency syndrome-related complex, and dose interruptions of zidovudine. Thirty-six (17%) of 210 patients who received trimethoprim-sulfamethoxazole prophylaxis developed PCP vs 299 (36%) of 838 who never received trimethoprim-sulfamethoxazole (odds ratio, 0.48). One hundred seven (22%) of 483 patients who ever received aerosol pentamidine prophylaxis developed PCP vs 228 (40%) of 565 who did not receive aerosol pentamidine (odds ratio, 0.55). In a time-dependent Cox proportional hazards analysis, trimethoprim-sulfamethoxazole (relative hazard, 0.21; 95% confidence interval [CI], 0.11 to 0.4) and aerosol pentamidine prophylaxis (relative hazard, 0.25; 95% CI, 0.16 to 0.39) were associated with decreased risk of PCP. Pneumocystis carinii pneumonia during follow-up was strongly associated with death when controlling for other factors (odds ratio, 1.8). For all patients, aerosol pentamidine prophylaxis was associated with a reduced risk of death during follow-up (relative hazard, 0.59; 95% CI, 0.44 to 0.78), while trimethoprim-sulfamethoxazole showed a weaker association (relative hazard, 0.74; 95% CI, 0.54 to 1.1). However, there was a significantly reduced risk of death overall for patients who consistently used trimethoprim-sulfamethoxazole (relative hazard, 0.55; 95% CI, 0.35 to 0.88) or aerosol pentamidine (relative hazard, 0.57; 95% CI, 0.42 to 0.77) and this was most pronounced in patients with a baseline history of PCP. DISCUSSION AND CONCLUSIONS: Pneumocystis carinii pneumonia was common in advanced HIV infection treated with zidovudine. Prophylaxis with trimethoprim-sulfamethoxazole and aerosol pentamidine both were associated with a decreased likelihood of PCP, and consistent use of each was associated with improved survival. Prophylaxis for PCP is associated with prolonged survival for patients with advanced HIV disease.

AIDS-Related Opportunistic Infections↗
PubMed1992

Natural history of advanced HIV disease in patients treated with zidovudine. The Zidovudine Epidemiology Study Group.

OBJECTIVE: To describe the natural history of advanced HIV disease in patients treated with zidovudine. DESIGN: Longitudinal, observational study. SETTING: Twelve academic and community-based sites. PATIENTS, PARTICIPANTS: Eight hundred and sixty-three patients with AIDS or AIDS-related complex (ARC) with a CD4+ lymphocyte count less than 250 x 10(6)/l, who first received zidovudine between 15 April 1987 and 14 April 1988. MAIN OUTCOME MEASURES: Survival, progression to AIDS and first development of specific opportunistic illness. RESULTS: Median survival after initiation of zidovudine therapy ranged from greater than 900 days in patients with a baseline CD4+ lymphocyte count greater than or equal to 150 x 10(6)/l to 560 days in patients with a CD4+ lymphocyte count less than 50 x 10(6)/1. Other factors associated significantly with poorer survival were diagnosis of AIDS (versus ARC), baseline age greater than or equal to 40 years, hematocrit less than 35%, and diminished functional status. In patients with ARC at enrollment, median time of progression to AIDS ranged from 810 days in patients with a CD4+ lymphocyte count greater than or equal to 150 x 10(6)/l to 310 days in patients with a CD4+ lymphocyte count less than 50 x 10(6)/l. Rates of development of specific opportunistic infections or neoplasms and HIV encephalopathy were determined for different baseline CD4+ lymphocyte count ranges. Myelosuppression was significantly more common in patients with CD4+ lymphocyte counts greater than or equal to 100 x 10(6)/l. Sixty-five per cent of patients with a CD4+ lymphocyte count greater than or equal to 100 x 10(6)/l and 51% with a CD4+ lymphocyte count less than 100 x 10(6)/l continued to receive zidovudine 2 years after starting therapy. CONCLUSIONS: We describe the natural history of a cohort of patients treated with zidovudine for advanced HIV disease. These CD4+ lymphocyte count-stratified estimates of disease progression should provide prognostic information useful in the clinical management of advanced disease and the design of future studies.

AIDS-Related Complex↗
PubMed1991

mu-receptor mediates elevated glucose and corticosterone after third ventricle injection of opioid peptides.

Four experiments were done to determine which receptor type(s) mediates the effects of third ventricular microinjections of four opioid peptide agonists on blood levels of glucose, free fatty acids, and corticosterone. Tests were performed in unanesthetized adult male albino rats having chronic intraventricular cannulas; blood samples were taken from the tail tip at 0, 15, 30, 60, 90, and 120 min postmicroinjection. In experiment 1, the agonists DAGO (Tyr-D-Ala-Gly-N-methyl-Phe-Gly-ol), beta-endorphin, DSLET (d-Ser2-Leu-enkephalin-Thr), and dynorphin A-(1-17) (0, 0.3, 1, 3, and 10 nmol/rat) produced three distinct patterns of changes in serum glucose, free fatty acid, and corticosterone values. Experiment 2 showed that the effects of DAGO and beta-endorphin were inhibited by prior injection with the opiate-receptor blocker naloxone (1 mg/kg sc) and that the effects of dynorphin were not diminished. Experiment 3 determined that dynorphin effects were also not diminished by naloxone given intraventricularly. Experiment 4 found that blockade of the mu-receptor by intraventricular pretreatment with the specific antagonist beta-funaltrexamine (20 micrograms/rat, 24 h before) completely abolished the effects of DAGO and beta-endorphin on glucose and corticosterone. The mu-receptor is critical to the mediation of the hyperglycemia and hypercorticosteronemia induced by the central administration of opiate agonists. These results imply that mu-opioid binding sites previously identified in central autonomic regions may be involved in the regulation of circulating glucose and corticosterone.

Animals↗
PubMed1991

Long-term safety and efficacy of zidovudine in patients with advanced human immunodeficiency virus disease. Zidovudine Epidemiology Study Group.

An epidemiologic study was initiated in 1987 to evaluate the long-term safety and efficacy of zidovudine in patients with advanced human immunodeficiency virus disease. Data from 886 patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex and CD4+ lymphocyte count less than 0.25 x 10(9)/L are reported. Eighteen-month survival was 67% for the cohort. Pretreatment factors associated with increased survival time included index diagnosis of AIDS-related complex, hematocrit of 0.35 or greater, CD4+ lymphocyte count of 0.15 x 10(9)/L or greater, high functional status, and time from diagnosis of AIDS to treatment of less than 60 days. By proportional hazards analysis, development of serious anemia was the most significant factor associated with early death. Receiving zidovudine for a high proportion of time significantly improved chances of survival even if anemia developed. Serious leukopenia occurring in 37% and serious anemia occurring in 32% of patients. Nonhematologic adverse events were uncommon and no previously unreported adverse events were seen.

Adult↗
PubMed1979

Activation by sanguinarine of active sodium efflux from frog skeletal muscle in the presence of ouabain.

1. Applied to intact Na-rich muscle cells, sanguinarine causes an increased 22Na efflux in the presence or absence of extracellular K+ or of ouabain. 2. The increased 22Na efflux does not represent Na:Na exchange as indicated by the fact that it is not associated with an increase in one-way isotopic Na influx nor is it abolished by the absence of external Na+. 3. In both K-free Ringer and K-free Ringer containing ouabain, sanguinarine not only increases one-way efflux of 22Na, it also induces net efflux of Na+ in the face of both an electrical and a concentration gradient. Moreover, the induction of net Na+ efflux occurs in the face of an approximately fourfold increase in PNa. These surprising results lead to the conclusion that, contrary to all experiments, sanguinarine induces active Na+ efflux even in K-free Ringer containing 10(-3) M-ouabain. 4. Sanguinarine depolarizes the Na-loaded muscle to approximately the same value, -54 mV, regardless of the presence or absence of extracellular K+. This depolarization is most likely secondary to the increase in PNa. 5. Sanguinarine causes a net loss of K+, presumably secondary to the depolarization. 6. The stimulation of net Na+ efflux is not correlated with the depolarization. The stimulation in K-free conditions (with or without ouabain), which is associated with the largest depolarization, produces an increment in net Na+ efflux which is not significantly different from the increment in net Na+ efflux in 10 mM-K+ Ringer where the depolarization is smallest. 7. Although sanguinarine increases active Na+ efflux in intact cells, it inhibits the isolated (Na+ + K+)-ATPase, presumably due to interaction with a site on the inner face of the membrane fragment. 8. The surprising stimulation of active Na+ efflux in the presence of 10(-3) M-ouabain must be due to interaction of sanguinarine with a site on the outer face of the membrane, perhaps the K+ activation site. It seems probable that the component of active Na+ efflux induced by sanguinarine is mediated by the Na pump. Sanguinarine may produce a K+-like effect upon the Na pump with consequent unbinding of ouabain.

Alkaloids↗
PubMed1979

Mechanism of insulin action on resting membrane potential of frog skeletal muscle.

At a concentration that stimulates the Na pump, insulin hyperpolarizes the plasma membrane of frog sartorius in the presence of substrate-free Ringer. The hyperpolarization ranged from 3.5 to 7.3 mV and averaged 4.7 mV. Ouabain, 10(-4) M, completely blocked the effect of insulin on the membrane potential. Moreover, ouabain completely reversed the insulin-induced hyperpolarization within 20 min. The hyperpolarization produced by insulin was not associated with a detectable increase in the ratio of K+ permeability to Na+ permeability nor with a detectable increase in the concentration of intracellular K+, although a depletion of K+ near the external surface of the membrane cannot be excluded. The results clearly indicate that the hyperpolarization is secondary to stimulation of the Na pump by insulin.

Animals↗